Machine for cutting the teeth of spur-wheels.



A. DENKER. MACHINE FOR CUTTING THE TEETH 0P SPUR WHEELS. APPLICATIONFILED MAY 6, 1910.

1, 1 1 5,909. Patented Nov. 3, 1914.

2 SHBETFSHEET 1.

w a wig A. DENKER. MACHINE FOR CUTTING THE TEETH OF SPUR WHEELS.

APPLICATION FILED MAY 8, 1910.

Patented Nov. 3, 1914.

2 SHEETSSHEBT T" "UNITED STATES PATENT OFFICE.

AUGUST DENKEB, 0F BATH, NEAR DUSSELD ORF, GERMANY, ASSIGNOR TO RUDOLFDIETEL, OF IDP'SSELDOBF-OBERGASSEL, GERMANY.

MACHINE FOB CUTTING THE TEETH OF SPUR-WHEELS.

Specification of Letters Patent.

Patented Nov. 3, 191-4.

Application filed May 6, 1910. Serial No. 559,676.

. To all whom it ma concern:

' wheel blank fixed on a worktable that is capable of being fed acrossthe bed of a machine and also of being rotated on its own am's oppositea reciprocating cutting tool.

This invention is applicable to machines of the'type in which the wheelblank can be given a combined rotation and cross feed of such a kindthat a tooth space will be finished before the wheel blank isrotatedthrough a distance equal to the pitch of the teeth to be cut.

The improvements consist in connecting the gearing that rotates theworktablewith the cross feed gearing by means of a clutch which on beingdisconnected, allows the gearing that rotates the worktable to servealso to rotate the worktable through a distance equal to the pitch ofthe teeth to be cut. The speed ratio of the cross feed gearing, and. thespeed'ratio of the gearing for rotating the worktable may be variedeither each alone or both to suit the number of teeth, or their pitch orboth, by changing the wheels of the corresponding gearings.

In the accompanying drawings which illustrate by way of example oneformof the present invention, Figure 1 is a side ele-' vation of theimproved machine, in which only those parts are shown which arenecessary for understanding the invention. Fig. 2 is a partialhorizontal section of the machine with the wheel blank removed 3 is adiagrammatic plan showing the position of the tool about to make thefirst cut in a solid wheel blank. Fig. 4: is a diagram-' matic planshowing the position of the tool when the first tooth has been cut; andFig. 5 is a sectional view of the whole; gearing extended in line (thatis, not projected).

Fig;

has the general arrangement of a vertical slotting machine. Thehorizontal worktable is mounted on the bed of the The improved machinein the form shown machine and is capable of being fed along and alsoacross the bed, and of being rotated on its own vertical axis. The meansfor feeding the table-along the bed are-not shown, because they have .noessential relation to the subject matter of the present inventlon.

a is a shaft mounted on one side of the machine framing, and from whichthe cross feed and the rotation of the worktable are' derived.

7) is a pawl actuated at each stroke of the I I tool ram by means of aconnecting rod from the driving' shaft of the machine for operating aratchet wheel a that is 'fixed on the shaft 0, whereby the. shaft 0 isrotated intermittentlyat the end of each stroke of the tool. Therotation of the shaftc is transmitted through bevel wheels J to a.

shaft 6 and thence through intermediate gears of variable speed ratio toa cross feed screw 21. The worktable receives its cross feed through anutformed on it engaging the cross feed screw Therotation of the shaft-e is also transmitted through a toothed wheel f to a toothed wheel 9which is loose on a pin it fixed in the framing-of the machine. Thewheel g carries one-half of a clutch 112. whose other half is capable ofrotating with and of sliding along the said pin h. This pin is connectedwith a Worm shaft 1 through suitable gearing at having a variable speedratio; and the coacting faces of the clutch are so constructed that theywill be brought into engagement with each other only when in apredetermined posi tion. This engagementis preferably effectedautomatically, for example, by means of a suitable spring a; bearingagainst the clutch.

The speed ratios of the gearing between the shaft e and the cross-feedscrew 1'- and of that between the clutch m and the 'worm shaft k Z, maybe varied by changing a pair of toothed wheels mounted on one of theshafts. The worm k engages a worm have a relation to the tool such as toimpart to the wheel blank to be cut, a motion equivalent to the rollingmotion of a toothed wheel having the same pitch circle along a rack. Forthis purpose the speed ratios of the gearing producing the cross feedand rotary feed of the table must be such that the ratio of the speed ofrevolution of the cross feed screw 71 to the speed of revolution of theshaft 6 must be equal to the ratioof the pitch of the wheel to be cut tothe pitch of the driving worm wheel connected to the worktable. Further,the ratio of the speed of revolution of the clutch m to the speed ofrevolution of the worm is must be equal to the ratio of the number ofteeth of the wheel to be cut to the number of teeth of the driving wormwheel. Also, the speed of revolution of the wheel f must have a ratio tothe speed of revolution of the wheel 9 which is inverse to that of thepitch of the cross feed screw z' to the pitch of the worm is so as tocompensate for the difference be- .tween these last two pitches.Consequently the product obtained by multiplying the speed ratio of thegearing between the cross feed screw 2' and shaft e by the speed ratioof the gearing between the clutch m and worm k will be the speed ratioof the cross feed of the table to the peripheral velocity of the wormwheel. Now since the product of the multiplication is the ratio of thediameter of the pitch circle of the wheel to be cut to the diameter ofthe pitch circle of the driving worm wheel, the consequence is that thespeed of the cross feed of the wheel blank to be cut is equal to thespeed of revolution at the pitch circle, that is to say, the motion ofthe wheel blank is the same as the rolling motion of a toothed wheelhaving a pitch circle of equal diameter along a rack. If, for examplethe worm wheel on the worktable has 140 teeth with a pitch of 5 7:millimeters, that is a pitch circle diameter of 700 millimeters, and 1fit is desired to cut a wheel with 100 teeth of-a pitch of 12 '1:millimeters, that is a pitch circle diameter of 1200 millimeters, thenthe ratio of the speed of revolution of the cross feed screw '5 to thespeed of revolution of the shaft e must be as 12 to 5, and the ratio ofthe speed of revolution of the clutch m to the speed of 'revolution ofthe worm \Zc, must be as 100 to 14:0. The product of multiplication ofthese two ratios is and the ratio of 1200 to 700 will be the ratio ofthe speed of the cross feed of the worktable to the peripheral speed ofthe worm wheel at the pitch circle. Now since the ratio of the pitchcircle diameter of the wheel to be cut, to the pitch circle diam;- terof the worm wheel is likewise as 1200 to 700, it is clear that the ratioof the peripheral speed of the wheel to be cut to the peripheral speedof the worm wheel, will likewise be as 1200 to 700; that is to say, theperipheral speed at the pitch circle of the wheel to be cut, is equal tothe amount of cross feed of the worktable.

, The operation of the improved machine is as follows :-The wheel blankto be cut having been fixed on the worktable and brought into theposition shown in Fig. 3 relatively to the cutting tool, the machine isstarted. During the up and down move- 'ment of the cutting tool, thewheel blank receives a cross feed and is simultaneously rotated on itsown axis until it assumes the position shown in Fig. 4: relatively tothe cutting tool, which is thus caused to cut a tooth space in the wheelblank. The wheel blank is then moved back into its initial position bymeans of hand cranks placed on the end of the shaft Z or the cross feedscrew 2', after which the parts of the clutch m are disconnected, andthe shaft Z is rotated independently of the spindle i, until after therotating part of the clutch part has made a complete revolutionwhereupon the clutch m is automatically connected again. Since the speedratio of the clutch m to the work ]b' Z corresponds to the number ofteeth of the driving worm wheel, therefore after the clutch part hasmade a complete revolution, the wheel blank will have been rotatedthrough an angle corresponding to the pitch of the wheel to be cut, thatis in the example under consideration, through an angle of 3 degrees 36minutes, which corresponds to a pitch of 12. If it is desired to cuttoothed wheels having a different pitch or a different number of teeth,it will be necessary to change merely one pair of toothed wheels of thegearing between the shaft 6 and the screw 2' or one pair of toothedwheels of the gearing between the clutch m and the worm shaft 76 I. Whenboth. the pitch and the numberof teeth are different, one pair oftoothed wheels will have to be changed in both gearings.

The improved machine is very much simpler to construct and manipulatethan the existing shaping or slotting machines for cutting wheel teeth,and the present improvements are easily applicable to every existingshaping or slotting machine.

Having now described my invention what I claim as new and desire tosecure by Letters Patent is 1. In a machine for cutting teeth of spurgear wheels, the combination of a reciprocating cutting tool, a suitablesupport for the wheel blank to be cut, means to effect between saidblank and said tool an advance and return motion equivalent to therolling motion of a toothed wheel, of the same pitch diameter, along arack whereby a single complete tooth space will be cut by said tool, andthe blank restored to its initial position relatively to the cuttingtool, and means included in said first named means whereby said blankmay be indexed.

2. In a machine for cutting teeth of spur gear wheels, the combinationof a reciprocating cutting tool, a suitable support for the wheel blankto be cut, means to impart thereto a cross-feed, and means tosimultaneously impart thereto rotation on its own axis, the resultantmotion imparted to the blank relatively to the cutting tool beingequivalent to the rolling motion of a toothed wheel, of the same pitchdiameter, along a rack whereby a complete tooth space will be cut bysaid tool, and means included in said last named means whereby saidblank maybe indexed.

3. In a machine f r cutting teeth of spur gear wheels, the cod catingcutting tool, a suitable support for .the wheel blank to be cut, meansto impart thereto a cross-feed, means to simultaneously impart theretorotation on its own axis, and disengaging means to normally connect saidcross-feed means with said means to impart rotation to the wheel blank.

4. In a machine for cutting teeth of spur gear wheels, the combinationof a reciprocating cutting tool, a suitable support for the wheel blankto be cut, gearing to effect between said blank and said tool an ad-Vance and return motion equivalent to the rolling motion of a toothedwheel, of the same pitch diameter, along a rack, whereby a singlecomplete tooth space will be cut by said tool and the blank restored toits initial position relatively to the cutting tool, and means includedin said gearing whereby a portion thereof may be rendered temporarilyinoperative and the said wheel blank indexed through the continuouslyoperative portion of said gearing.

5. In a machine for cutting teeth of spur gear wheels, the combinationof a reciproeating cutting tool, a suitable support for the wheel blankto be out, means toimpart thereto a cross-feed, means to simultaneous-1y impart thereto rotation on its own axis, a clutch normally connectingsaid cross-feed means with said means to impart rotation to the wheelblank and adapted to be disengaged, and-means to automatically connectsaid clutch when the same has made a complete revolution,

6. Ina machine for cutting teeth of spur gear wheels, the combination ofa recipro" eating cutting tool, a suitable the wheel blank, gearing forimparting theretoa cross-feed, gearing for rotating bination of areciprosupport for A connecting the cross-feed gearing and said rotatinggearing and adapted to be disengaged, and means whereby the rotatinggearing may be actuated to rotate the support on its axis and throughthe angular amount of the pitch of the teeth to be cut.

7. In a'machinefor cutting teeth of spur gear wheels, the combination ofa reciproeating cutting tool, a suitable support for the wheel blank,gearing for imparting thereto a cross-feed and including a pair ofchange wheels, gearing for imparting rotation to said support on itsaxis and including a pair of change wheels, and a clutch for connectingthe cross-feed gearing with the rotating gearing.

8. In a machine for cutting teeth of spur -gear wheels, the combinationof a reciprocating cutting tool, a suitable support for the wheel blankto be cut, a feedscrew to impart a cross-feed motion to said support, aworm wheel and worm shaft to rotate the support, and intermedi-. ateconnecting gearing whose combined velocity ratio is equal to the ratioof the pitch circle diameter of the wheel to be cut to the pitch circlediameter of the worm wheel multiplied by the ratio of the pitch of theworm Wheel to the pitch of the cross-feed screw; change gearing foreffecting the cross-feed and having a velocity ratio equal to the pitchof the worm wheel to the pitch of the wheel to be cut; change gearingfor effecting the rotation of the wheel blank support and having avelocity ratio equal to the number of teeth of the wheel to be cut tothe number of teeth of the worm wheel; and a fixed gearing connectingsaid two sets of change gearing and having a velocity ratio equal to theratio of the pitch of the worm wheel to the pitch of the feed screw. q i

9. In a machine for cutting teeth of spur gear wheels, the combinationof a reciproeating cutting tool, a suitable support-for the wheel blankto be cut, a feed screw to impart a cross-feed motion to said support, awormwheel and worm shaft to rotate the support, and intermediateconnecting gearing whose combined velocity ratio is equal to the ratioof the pitch circle diameter of the wheel to be cut to the pitch cirolediameter of the worm wheel multiplied by the ratio of the pitch of theworm wheel to the pitch of the cross-feed screw change gearing foreifecting' thetross-feed and having a velocity ratio equal to the pitchof the Worm wheel to the pitch of the wheel to be cut; change gearingfor effecting the rotation'of the wheel blank support and having avelocity ratio equal to the number of teeth of the wheel to be cut tothe number of teeth of the worm wheel afixed gearing connecting saidsets of change gearing 1 and having a velocity ratio equal to th ratioof the pitch of the Worm Wheel to the pitch of the feed screw; anddisengaging means between said fixed gearing and 5 said change gearingfor rotating the support.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

AUGUST FUGGER.

